The Relation between Urinary Tract Infection and Febrile Seizure.

Objectives
Febrile seizure is the most common type of seizure among children. Identification of factors involved in febrile seizure is highly critical. The present study was conducted to determine the association between children's urinary tract infection and febrile seizure.


Materials & Methods
In this case-control study, 165 children with simple febrile seizure (case group) were compared with 165 children with fever and without seizure (control group) in terms of urinary tract infection (UTI) in Qazvin, central Iran in 2015-2016. The age of children was between 6 months to 5 yr.


Results
Among 165 children with febrile seizure, 25 (15.2%) had urinary tract infection. In the control group, only 2 patients (1.2%) had UTI. There was significant difference between two groups regarding urinary tract infection (P=0.001). Among 25 children with UTI in the case group, 17 children (68%) had acute pyelonephritis, and the remaining 8 children (32%) had cystitis. The two patients with UTI in control group had cystitis (P=0.055).


Conclusion
Urinary tract infection could be a risk factor for febrile seizure. Therefore, all patients with febrile seizure are examined in terms of urinary tract infection.


Introduction
Febrile seizure is the most common type of seizure among children. Febrile seizure refers to a type of seizure which occurs if temperature of child's fever is equal to or higher than 38 °C. These patients have not central nervous system infection (such as meningitis, encephalitis, etc.), metabolic The Relation between Urinary Tract Infection and Febrile Seizure disease and afebrile seizure. The disease is usually observed among children within age range of 6 to 60 months. The age peak of febrile seizure is 18 months old.
The prevalence of febrile seizure ranges from 2% to 5% (1)(2)(3)(4). Febrile seizure is divided into simple and complex types. Regarding the simple type, seizures are usually of tonic-clonic type. The seizures do occur once a day and take less than 15 min. Concerning complex type of seizure, it is usually focal and occurs more than once a day and each seizure takes more than 15 min (1-2). Febrile seizure usually has a good prognostic outcome, but it may be lead to epilepsy in 2%-7% of the cases (1).
Although the etiology of febrile seizure is imprecise, some reports point to the role of certain factors such as genetics, infections and deficiency of certain trace elements (5)(6)(7). Considering the role of some viral infections in febrile seizure (6), the question is raised for us that "Do bacterial infections such as UTI could provide the conditions for febrile seizure?" Urinary tract infection (UTI) is one of the common diseases of children. In 75%-90% of the cases, Escherichia coli is the agent.
Considering the high prevalence of febrile seizure and significance of identification of influential factors, the present study was conducted.

Materials & Methods
In this case-control study, 165 children with simple P-value of less than 0.05 was considered significant. The most common organism causing UTI in children was E. coli. The most sensitivity was seen to amikacin, gentamicin, ceftriaxone and nalidixic acid, and the highest drug resistance was found to ampicillin, cefalexin, and trimethoprimsulfamethoxazole.

Discussion
The findings of present study suggested that the prevalence of UTI in children with simple febrile seizure was higher than control group. The findings of studies on the role of UTIs in febrile seizure are contradictory (9-12, 15, 16). A study was conducted on 137 children with simple and complex febrile seizure with age range of 1 month to 5 year. The prevalence of UTI in children with febrile seizure was 6.6%. The author's recommended urinalysis and urine culture test for all patients with febrile seizure so that probable UTI cases could be identified (9). In another study conducted on 228 children with febrile seizure in the age range of 1-71 months (mean age: 24 months), 5%-12% of children had bacteriuria. The authors emphasized the significance of UTI diagnostic tests for children with febrile seizure (10).   Probability of kidney scarring in low-age children is higher than older children. In addition, patients with UTI may be inflicted with urinary system abnormalities such as reflux and hydronephrosis.
These abnormalities might increase the probability of recurrence of UTI and also add to likelihood of kidney scarring (17).
Among limitations of present study we can point to the following cases: 1) Conducting the study solely in one center; 2) Lack of study on children with complex febrile seizure. The authors recommend further studies in this regard: such as multi-center study, study on complex febrile seizures and study on pathophysiology of this association.
In conclusion, considering the high prevalence of UTI (15.2%), we recommend the urinalysis and urine culture test for all children with febrile seizure, so that UTI cases could be identified.